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为了分析热量通过织物时的热传递情况,采用ANSYS建立皮肤、空气层与织物的有限元模型,模拟分析了不同织物、不同空气层厚度及不同对流条件下模型内部和织物外表面的瞬态温度分布情况。同时探索了空气等效导热系数的增大对热量传递的影响。结果表明:空气层的厚度对织物热传递有影响,随着空气层厚度的增加,热传递达到平衡时的时间逐渐增长,织物外表面的温度逐渐降低,且下降的梯度逐渐减小;热对流的存在缩短了热量传递达到平衡时的时间,且对流换热系数越大,织物表面温度越低;增大空气的等效导热系数,热量传递的距离更远。为了验证模拟的正确性,在人工气候室进行了恒温板实验,结果发现模拟结果和实验数据相关性良好。 相似文献
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为研究一台带内拉筒的钢制焊接烘缸的应力分布情况和结构安全性,采用有限元法,对烘缸的应力进行了有限元计算和分析,得到了烘缸的应力分布图,并对危险区域的应力强度进行了分析和评定。结果表明:最大应力出现在烘缸盖板与外筒体及内拉筒连接处的环带和盖板人孔开孔处的内侧区域,该区域是影响结构安全的危险区域。 相似文献
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针对磁悬浮式驱动织针运动过程中温度变化导致的散热问题,从摩擦热流生成、温度场与应力场的数值计算等方面提出织针滑动摩擦的分析方法,揭示磁悬浮式驱动织针发生热失效的机理.以ANSYS14.0有限元分析软件为仿真平台,建立织针装置的参数化模型,分析织针在成圈、集圈及浮线3种运动过程中的瞬态温度分布和应力分布.结果表明:3种运动状态刚完成时瞬态的最低温度分别为13℃、17℃、18℃,最高温度分别为46℃、59℃、63℃,满足织针材料对温度的要求;织针最大应力在x方向为3.12×10-4 MPa,表现为压应力,满足织针材料对强度的要求;可为磁悬浮织针选材和结构设计提供参考. 相似文献
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以平板塑件的注塑模具为研究对象,运用ANSYS对其进行瞬态热分析,模拟注塑过程中各时刻模具的温度分布情况,并在模具温度最大时刻进行稳态静力分析,找出应力集中区域,为模具的疲劳设计提供一定的依据。 相似文献
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文章建立某重型汽车离合器摩擦片有限元模型,确定载荷及边界条件,运用ANSYS软件中的Lanczos算法进行模态计算,求得重型汽车离合器摩擦片的前几阶固有频率和振型,从而为其设计的改善提出建议。 相似文献
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介绍了高速木工机械电主轴的特点,分析了高速木工机械电主轴单元的热变形机理.建立了某型高速木工机械电主轴热态特性有限元分析模型,利用ANSYS进行了稳态温度场分析,并利用分布加载瞬态热分析模拟了机床的实际工作情况,得到了电主轴的温度场分布情况,为有效控制电主轴的温升提供了理论依据.在分析结果的基础上,提出了改善电主轴热态... 相似文献
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针对现有羽绒制品保暖性测试方法的测试时间较长、成本较高等不足,提出一种数值模拟测试方法。采用ANSYS有限元软件建立“羽绒-织物-皮肤”的三维几何模型,模拟分析不同织物、不同填充密度、不同绗缝数量条件下模型内部与外表面的温度分布特征,探究不同条件对热量沿厚度方向和宽度方向传递的影响,计算其保暖性,并进行实验验证。结果表明:羽绒填充密度增加,热量沿模型厚度方向的传递距离增大,外表面温度及热流密度减小;绗缝数量增加,热量沿模型厚度方向的传递增大,沿模型宽度方向的传递距离减小,外表面温度及热流密度逐渐增大;织物对羽绒制品保暖性的影响较小;模拟结果与实验结果的最大相对误差为4.79%,二者吻合度较好。 相似文献
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Theoretical analysis has been carried out to study the role of ceramic plates (alumina and SiC) and pulsed microwave heating of pork meat (Pork Luncheon Roll (PLR) and White Pudding (WP)) samples. Spatial hot spots occur either at the center of the sample or at the outer face or at the face attached with alumina plate and application of pulsing minimizes formation of hot spots within meat samples. Pulsing of microwave is characterized by set point for temperature difference (ΔTS) and on–off constraints for temperature (T′). It is found that alumina plate with higher ΔTS and lower T′ may be recommended for thick meat samples (both WP and PLR) whereas for thin meat samples, lower ΔTS with alumina plate/without plate may be preferred. It is also observed that SiC plate may be selectively used with ΔTS = 20 K for both the pork meats. The distributed microwave incidence is found to be effective due to lesser degree of thermal runaway in absence of pulsing for both meat samples. 相似文献
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异形竖板降膜蒸发器的性能研究 总被引:1,自引:0,他引:1
两块薄不锈钢周边缝焊后,在特制胎具中充胀成酒窝状壁面的中空传热元件,其外壁进行降膜蒸发。本文介绍了异形竖板降膜蒸发器的降膜流动、传热、破裂以及结垢性能。同时将异形竖板降膜蒸发器与普通管式降膜蒸发器在液膜流动与结垢性能上进行了比较,该设备在食品工业中有广泛的应用前景。 相似文献
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HEAT TRANSFER COEFFICIENT FOR COOKIE SHAPED OBJECTS IN A HOT AIR JET IMPINGEMENT OVEN 总被引:1,自引:0,他引:1
Correlations for average heat transfer coefficient for cookie shaped objects in a hot air jet impingement oven were obtained using aluminum cookie models. The study was carried out in a pilot plant scale hot air jet impingement oven. The effects of individual cookie position, presence of surrounding cookies, air velocity, air temperature and rotation of the oven plate on average surface heat transfer coefficient were investigated. The value of the heat transfer coefficient ranged between 100–225 W/m2K and was found to be a strong function of jet air velocity. The impact of surrounding cookies on the heat transfer coefficient was more for smaller cookies, which had larger cookie‐to‐cookie spacing. 相似文献
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一种板式间接蒸发冷却器数学模型的验证 总被引:2,自引:0,他引:2
对J.Stoitchkov建立的关于叉流板式间接蒸发冷却器的数字模型进行了理论计算及实验验证,结果表明,理论值与实验值的相对误差不大于10%.用该模型计算了一次风量、二次风量、淋水量及隔板厚度对一次风出口温度的影响. 相似文献
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介绍了一个影响人体热平衡的参数模型。利用热阻湿阻测试仪对热阻进行测试,结果表明:在织物参数中,线圈模量、织物面密度、孔隙度、覆盖系数对织物的热传递性能影响最大。 相似文献
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P De Jong S. Bouman H J L J VAN DER Linden 《International Journal of Dairy Technology》1992,45(1):3-8
The relationship between the denaturation of β-lactoglobulin (β-lg) and the deposition of milk constituents in a heat exchanger was investigated. Experiments were carried out on a plate heat exchanger with skim milk by applying different temperature-time combinations in the temperature range 70 to 122°C. The aggregation of β-lg was measured by high performance gel permeation chromatography, and the amount of deposits on the plates of the heat exchanger was determined by chemical oxygen demand measurements. Based on the results of the experiments, a fouling model at temperatures up to 100°C is proposed and some measures to reduce the amount of deposits by more than 50% are given. 相似文献
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Details are given of a new thermal-transmission apparatus which is automatic in operation, which does not depend on the measurement of a heat flux, and which requires no guard plates to eliminate edge heat losses. The apparatus works on the principle that for conductors in series with respect to direction of heat flow, the ratio of the temperature drop across them equals the ratio of their thermal resistances, and the only measurements involved are those of temperature in the equilibrium state. The apparatus is suitable for testing the thermal-transmission properties of textile materials up to at least 1 in. thick. Data are presented for the thermal-transmission properties of timber and of plate glass determined with the new apparatus. 相似文献